William Byron enjoyed a walk-off moment Sunday as he captured the NASCAR Cup Series victory at Martinsville Speedway to vault himself into a spot in the Championship 4.

Byron, who wasn’t going to be able to make it to the final playoff round on points, nudged his way by Ryan Blaney and led the final 44 laps.

The four drivers vying for the title next Sunday at Phoenix Raceway will come from two organizations: Hendrick Motorsports (Byron, Kyle Larson) and Joe Gibbs Racing (Denny Hamlin, Chase Briscoe). Eliminated from title contention were Team Penske drivers Joey Logano and Blaney, Hendrick’s Chase Elliott and JGR’s Christopher Bell.

Here are my takeaways:

1. Byron Biggest Wins At Paperclip

Byron has won back-to-back Daytona 500s but Martinsville, the shortest track on the circuit, has been the place of some of his biggest victories.

“William had the race of his career today,” said team vice chairman Jeff Gordon, a four-time Cup champion.

The place where he first attended races as a boy (Byron credits learning how to race the track from those early experiences), Martinsville was the place where Byron’s mother collapsed from a stroke-like event (unbeknownst to Byron as he raced) caused by a brain tumor and then a year later Byron won with his mom atop the pit box. Byron still considered that his biggest win at Martinsville, even after the one on Sunday.

Byron also won the April 2024 race at Martinsville where Hendrick had hundreds of employees in attendance as part of its 40th anniversary celebration. Martinsville is the place of Hendrick’s transformative moments — team owner Rick Hendrick’s home track, the site of his organization’s first win when it was on the brink of ceasing operations and where a Hendrick plane crashed nearby in 2004 en route to the race, killing 10 people, including Hendrick’s son, brother and two nieces.

2. No Four In A Row For Penske

Logano (2022 and 2024) and Blaney (2023) had combined to win the last three titles and if they could have made the championship race, they would have been the favorite because of their prowess on flat short tracks such as Phoenix.

But neither made it as they faced a must-win scenario. Blaney rallied from starting 31st but couldn’t hold off Byron. He said it stung but Byron had the better car. Blaney couldn’t even hold a grudge against Byron for the shove for the winning pass.

“I don’t blame him for taking that,” Blaney said. “I had kind of lost momentum. I would have done the same thing.”

3. JGR Has To Worry

Neither Briscoe nor Hamlin finished the race Sunday as engine failures ended their day. It wasn’t immediately clear if they were the same issue.

Hamlin, who has 60 career Cup wins but has never won a title, could think “What will go wrong at Phoenix?” as he has had a few issues in the last several weeks from power steering to a throttle clog to the engine issue.

As a veteran, Hamlin knows he can only control so much.

“As long as we can keep it together, we’re fast and capable,” Hamlin said.

4. Bell Disappointed Again

Bell missed the Champ 4 for the second consecutive year as his seventh-place finish wasn’t good enough with Byron’s victory knocking him out. Bell entered the race one point ahead of Larson, but Larson finished fifth and earned more stage points to eliminate Bell by seven points.

Bell’s car faded a little quicker than the other top cars, so there wasn’t much he could do unless Larson had an issue or Byron (or another driver from below the cutline) didn’t win.

“We practiced in the teens, we qualified in the teens, and kind of raced back there most of the day,” Bell said.

4 ½. What’s Next

The 2025 NASCAR Cup season finale, a 312-lap race at the 1-mile Phoenix Raceway. 

The driver among the four finalists who finishes the best among them (there will a field of 36-40 drivers) will be crowned the champion.

Only Larson has a championship among the four with Hamlin, Briscoe and Byron all looking for their first title.

Bob Pockrass covers NASCAR and INDYCAR for FOX Sports. He has spent decades covering motorsports, including over 30 Daytona 500s, with stints at ESPN, Sporting News, NASCAR Scene magazine and The (Daytona Beach) News-Journal. Follow him on Twitter @bobpockrass.